Coil bobbin for brushless alternator

ABSTRACT

A coil bobbin for a brushless alternator includes an integrally formed one piece bobbin body that has a first end, a second end and a central passage that extends from the first end to the second end. A coil support portion of the body is positioned at the first end and has a first cylinder of a first diameter bordered by flanges which extend past the first cylinder. A base portion of the body is positioned at the second end. A bobbin extension portion is positioned between the coil support portion and the base portion. The bobbin extension portion includes a second cylinder of a second diameter which is smaller than the first diameter.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/527506, filed Jun. 19, 2012, the disclosure of which is herebyincorporated by reference herein its entirety.

FIELD

There is described a coil bobbin that was developed for use in abrushless alternator.

BACKGROUND

It is recognized that the coil bobbin configuration of a brushlessalternator can have a significant effect on performance. Examples ofunique coil bobbin configurations are U.S. Pat. No. 6,967,423 (Kuroda etal) entitled “Brushless Alternator Field Coil Bobbin Apparatus” and U.S.Pat. No. 7,759,838 (Bradfield et al) entitled “Coil Support For RotatingElectrical Machine.” There will hereinafter be described a unique coilbobbin that was developed to be both compact and inexpensive enough forlarge scale usage on industrial skid engine power units.

SUMMARY

There is provided a coil bobbin for a brushless alternator. The coilbobbin has an integrally formed one piece bobbin body with a first end,a second end and a central passage that extends from the first end tothe second end. A coil support portion of the body is positioned at thefirst end. The coil support portion has a first cylinder of a firstdiameter bordered by flanges which extend past the first cylinder. Abase portion of the body is positioned at the second end. A bobbinextension portion is positioned between the coil support portion and thebase portion. The bobbin extension portion has a second cylinder of asecond diameter smaller than the first diameter.

The coil bobbin described above allows for a very compact design whichis compatible with existing mounting methods of current brushedalternators. The coil bobbin was designed to allow greater air flowthrough the alternator while still allowing enough room in the back ofthe rear housing for all the electronics to be mounted inside the unit.We achieved this design by mounting the coil support portion on thebobbin extension portion or “stand-off” portion. The bobbin extensionportion or “stand-off” portion has a smaller diameter than the coilsupport portion to allow more room for electronic components and moreair to flow over electronics and through the alternator which is beingpulled through the alternator by a fan mounted externally on the frontof the alternator. The length of the bobbin extension portion or“stand-off” portion is such to position the coil bobbin properly insidethe spinning rotor assembly.

It is preferred that the base portion is a flange having two or moreflange segments. By cutting the flange into segments the base can beshaped to fit the open areas in the inside of and on the back end of therear housing that are left after the electronics are fitted in place.

It is also preferred that an alignment ring is secured to an exteriorface of the base portion. This is of assistance in centering the coilbobbin in an alternator.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features will become more apparent from the followingdescription in which reference is made to the appended drawings, thedrawings are for the purpose of illustration only and are not intendedto be in any way limiting, wherein:

FIG. 1 is a side elevation view of a coil bobbin for a brushlessalternator.

FIG. 2 is a bottom plan view, partially in section, of the coil bobbinfor a brushless alternator shown in FIG. 1.

FIG. 3 is a side elevation view, partially in section, of the coilbobbin for a brushless alternator shown in FIG. 1 positioned within analternator.

DETAILED DESCRIPTION

A coil bobbin for a brushless alternator generally identified byreference numeral 10, will now be described with reference to FIGS. 1through 3.

Structure and Relationship of Parts:

Referring to FIG. 1, a coil bobbin for a brushless alternator 10includes an integrally formed one piece bobbin body 12 which has a firstend 14, a second end 16 and a central passage 18 that extends from firstend 14 to second end 16. Bobbin body 12 defines a coil support portion20 and a bobbin extension portion 22 and has a base portion 24 at secondend 16. Coil support portion 20 of bobbin body 12 is positioned at firstend 14 and is made up of a first cylinder 26 of a first diameterbordered by flanges 28 which extend past first cylinder 26. Bobbinextension portion 22 is positioned between coil support portion 20 andbase portion 24 and has a second cylinder 32 of a second diameter whichis smaller than the first diameter. The positioning of bobbin extensionportion 22 creates a large opening for air flow and room for mounting ofelectronics such as voltage regulators and rectifiers (not shown infigures).

Referring to FIG. 2, base portion 24 of bobbin body 12 is preferably aflange 34 with two or more flange segments 36. By cutting flange 34 intoflange segments 36, base can be shaped to fit the open areas in theinside of and on the back end of the rear housing (not shown) that areleft after electronics are fitted in place. An alignment ring 38 issecured to an exterior face 40 of base portion 24 to assist in centeringcoil bobbin 10 in an alternator.

Referring to FIG. 3, coil support portion 20 is wound with wire 21 tomagnetize the rotor as is done in any brushless alternator. Referring toFIG. 2, the windings come through holes 42 for connection to a voltageregulator (not shown).

Operation:

Referring to FIG. 3, base 24 of coil bobbin 10 is mounted in analternator 100. Flange segments 36 allow base 24 to be shaped to fit theopen areas in the inside of and on the back end of the rear housing 110left after electronics (not shown) are fitted in place. Referring toFIG. 2, alignment ring 38 is positioned between base 24 and the mountingposition in the alternator (not shown in this figure) to assist incentering coil bobbin 10 within alternator 100. Referring to FIG. 3,bobbin extension portion 22 allows for increased air flow through coilbobbin 10 to electronics (not shown). A fan 114 positioned withinalternator 100 helps to create the air flow through coil bobbin 10.Bobbin extension portion 22 is of a length to position coil supportportion 20 properly inside a spinning rotor assembly 112.

In this patent document, the word “comprising” is used in itsnon-limiting sense to mean that items following the word are included,but items not specifically mentioned are not excluded. A reference to anelement by the indefinite article “a” does not exclude the possibilitythat more than one of the element is present, unless the context clearlyrequires that there be one and only one of the elements.

The scope of the claims should not be limited by the preferredembodiments set forth in the examples, but should be given a broadpurposive interpretation consistent with the description as a whole.

1-3. (canceled)
 4. A coil bobbin for a brushless alternator, comprising:a bobbin body having a first end, a second end and a central passagethat extends from the first end to the second end; a coil supportportion of the body at the first end, the coil support portioncomprising a first hollow cylinder having a first inner diameter andbeing bordered by flanges which extend past the first cylinder; a baseportion of the body at the second end; and a bobbin extension portionpositioned between the coil support portion and the base portion, thebobbin extension portion comprising a second hollow cylinder having asecond inner diameter that is smaller than the first inner diameter. 5.The coil bobbin of claim 4, wherein the base portion is comprised of aflange having a first side, a second side, and two or more flangesegments, wherein adjacent flange segments define open sections in theflange, the open sections being open between and through the first sideand the second side of the flange.
 6. The coil bobbin of claim 4,wherein an alignment ring is secured to an exterior face of the baseportion, whereby the coil bobbin is centered in an alternator.
 7. A coilbobbin for a brushless alternator, comprising: a bobbin body having afirst end, a second end and a central passage that extends from thefirst end to the second end; a coil support portion of the body at thefirst end, the coil support portion comprising a first cylinder of afirst diameter bordered by flanges which extend past the first cylinder;a base portion of the body at the second end; and a bobbin extensionportion positioned between the coil support portion and the baseportion, the bobbin extension portion comprising a second cylinder of asecond diameter smaller than the first diameter; the base portioncomprising a flange having a first side, a second side, and two or moreflange segments, wherein adjacent flange segments define open sectionsin the flange, the open sections being open between and through thefirst side and the second side of the flange.
 8. The coil bobbin ofclaim 7, wherein an alignment ring is secured to an exterior face of thebase portion, whereby the coil bobbin is centered in an alternator. 9.The coil bobbin of claim 7, wherein the first cylinder comprises a firsthollow cylinder having a first inner diameter and the second cylindercomprises a second hollow cylinder having a second inner diameter.